1. Technical Field
The present invention relates to a system for a floor covering comprising planar covering panels, such as slabs, tiles, or the like, made of marble or marble aggregate and attachment parts for connecting said covering panels to one another.
2. State of the Prior Art
In the case of covering panels such as tiles, small slabs, mosaic tiles and glazed tiles, according to a classic system, the covering panels are first applied on a bed previously prepared in a floor arranging the edges of one covering panel facing the edges of the adjacent covering panels, leaving a narrow gap between them, and then the facing edges of adjacent covering panels are grouted by filling the aforementioned gaps comprised between the edges with a grout based on lime, plaster and/or cement or the like. A drawback of this system is that the covering panels are not linked to one another, such that they can separate, the gap between them becoming wider.
Other systems for attachment contiguous covering panels to one another that are made of a hard material such as marble or a marble aggregate for floor covering are also known. Such systems have in common the fact that the edges of the covering panels are attached by means of the mutual fitting of respective recesses and projections. Nevertheless, due to the maneuver for carrying out said fitting or coupling, the recesses and projections on the edges of covering panels of a single part have the drawback of being very prone to sustaining breaks or spalling. Relatively sinuous or complicated auxiliary fixing elements are sometimes used to prevent this.
Document U.S. Pat. No. 4,840,825, for instance, relates to a tile for covering floors having a stone layer attached to a substrate made up of three sub-layers, each of them having substantially the same shape as the stone layer. A first sub-layer adjacent to the stone layer is aligned with the latter, a second intermediate sub-layer is displaced in two directions to define two projecting tongues from two edges and two grooves on the opposite edges. The third or outer sub-layer is displaced in one direction to define a projecting tab provided with two fixing holes. Therefore the tiles allow a fixing with the projecting tongues interlocking in the grooves of the adjacent tiles. The stone layer itself does not have any recess or projection for coupling it with another adjacent stone layer, but it has the drawback of needing said additional sub-layers which define the projections and grooves in order to perform the tongue and groove coupling with tiles adjacent.
On the other hand, document WO 01/38668 relates to a covering, particularly for a floor, ceiling or wall, which is characterized in that it comprises a number of successive solid covering panels of a single layer, and fixing elements. The fixing elements consist of supports which, by means of fixing portions, retain the panels in a disconnectable manner by coupling with connection elements formed through a portion of the thickness of the panels. The same document describes that the supports are fixed to a base surface and have end portions in the form of hooks which engage and hold a respective panel by opposite ends, and that each panel has profiled tongued and grooved opposite edges, which are susceptible to being coupled with another adjacent panel held in a similar manner. Nevertheless, this tongue and groove coupling of recesses and projections formed in the edges of covering panels of a single solid part has the drawback of being prone to breaking or spalling of the edges of the covering panels.
On the other hand, document DE-A-10355370 relates to a system for covering a floor comprising covering panels and attachment elements. The covering panels have an upper stone or ceramic layer, and a lower layer defining recesses in its edges. The attachment elements have holes for fixing them to a base surface and projections which are coupled to the recesses of the lower layers of two adjacent covering panels. In a coupled condition, the coupling elements are covered by the upper layers of the covering panels. This system has the drawback of needing a lower layer placed against the upper stone or ceramic layer.
Document EP 1146182 A2 discloses a floor covering system comprising adjacent flooring tiles made of a laminate material or a polymeric material such as a thermoplastic material having horizontal grooves in respective adjacent side edges and locking elements having projections inserted in said grooves lo lock the tiles to one another.
Document EP 0121915 A2 discloses a floor covering system comprising adjacent flooring boards made of wood, plastics or moisture-resistant fiber-material having horizontal grooves in respective adjacent side edges, and locking elements having projections inserted in said grooves lo lock the tiles to one another.
Document FR 1524707 A discloses a floor covering system comprising adjacent flooring boards made of solid wood or composite materials having horizontal grooves in respective adjacent side edges and locking elements having projections inserted in said grooves lo lock the tiles to one another.
However, such deep horizontal grooves of any of cited documents EP 1146182 A2, EP 0121915 A2 and FR 1524707 A, when mechanized in side edges of relatively thin solid marble or marble aggregate panels, renders the edge regions of the panels fragile under foot stepping or the like.
Document US 2007/107359 A1 teaches a floor covering system comprising a plurality of mutually adjacent flooring strip boards made of a HDF (High Density Fiberboard) or MDF (Medium Density Fiberboard) laminate material and locking elements engaging the boards to each other. A groove is formed in the vertical direction at a lower surface of each of the strip boards near side edges thereof, and said locking element comprises two projections extending from a bottom plate of the locking element which when assembling the system are inserted in respective of said grooves of adjacent strip boards. The grooves have an inner region wider than an open channel communicating therewith so that an inner wall of the grooves defines a hook portion, and the two projections of the locking element have a hook shape configured to lock in said hook portion of the grooves. A drawback with this floor covering system is that it cannot be applied to covering panels made of marble or marble aggregate because grooves having a hook portion in an inner wall thereof are very difficult, or almost impossible, to be mechanized in floor covering panels made of marble or marble aggregate.